Cu-catalyzed cross-coupling of unactivated secondary alkyl iodides with alkyl Grignard reagents in the presence of 1,3-butadiene as a ligand precursor was developed. The use of 1,3-butadiene resulted in improved yields of alkyl-alkyl products with improved selectivities.

Intermolecular Heck reaction of common alkyl halides, a longstanding problem in palladium catalysis, is realized with a simple Pd/dppf catalyst. Both primary and secondary alkyl halides are suitable for coupling with aromatic olefins. Single electron transfer from (dppf)Pd(0) to alkyl halide initiated the catalytic cycle and gave alkyl radicals.

Heiko Traupe, Universitäts-Hautklinik, Von-Esmarch-Strasse 56, D–4400 Münster (FRG); Rudolf Happle, Department of Dermatology, University of Nijmegen, Javastraat 104, NL-6524 Nijmegen (The Netherlands) Sir, The data of Unamuno et al. [8] on the high incidence of cryptorchidism in X-linked recessive ichthyosis are of considerable interest, in particular to those concerned with pediatric dermatol...

The conformation of the L-iduronate residue in non-sulphated di-, tetra- and hexa-saccharides and their alditol derivatives derived from rooster comb dermatan sulphate was investigated by 400 MHz 1H-n.m.r. spectroscopy. The ratio of conformational isomers is obtained by the average spin-spin coupling constants of a mixture of nearly isoenergetic conformers (1C4, 4C1 and 2S0). The non-reducing t...

To explore soil organic carbon (SOC) accumulation mechanisms, the dynamics of C functional groups and macroaggregation were studied synchronously through aggregate fractionation and (13)C NMR spectroscopy in sandy loam soil following an 18-year application of compost and fertilizer in China. Compared with no fertilizer control, both compost and fertilizer improved SOC content, while the applica...

different procedures for the syntheses of the title compounds were investigated. the best method for the preparation of the title compounds were the reaction of the readily available 2-formyl-1-methyl-5-nitroimidazole2- substituted-4-formylthiazoles with alkyl acetoacetate and alkyl aminocrotonate in boiling alcohol.

Alkyldihydroxyacetone-P (alkyl-DHAP) synthase, the enzyme that forms the ether linkage of alkyl and alk-1-enyl glycerolipids, has been solubilized from ehrlich ascites cell microsomes using Triton X-100 and acetone precipitation. the solubilized enzyme, which is stabilized by glycerol or ethylene glycol, was then purified further by chromatography on DEAE-cellulose, QAE-Sephadex, Matrex Red, an...

Plasma cholesterol sulfate concentration is increased in patients with recessive X-linked ichthyosis, a disease in which steroid sulfatase activity is absent. In these patients, cholesterol sulfate is found primarily in the low-density lipoprotein fraction of plasma, and the electrophoretic mobility of these lipoproteins is greatly increased.